This invention relates to network test instruments, and more particularly to devices to help locate a cable in an efficient manner.
In the installation and maintenance of networks or other telecommunication installations, it is often desirable or necessary to locate a particular cable associated with a particular network device. However, as the number of cables in a particular situation can be large, it becomes difficult to identify an individual cable of interest.
Applying a tone to a cable has been used in the telecommunications industry as a locating aid. A detector is used at locations remote from the application of the tone, to aid in locating the desired cable or wire pair of a cable. However, the tone does not work as well if the testing situation involves use of a hub.
Another method of locating a cable in a network installation involves providing link pulses on a network cable. The particular cable at the other end which is attached to a network device is then determinable by looking for and observing the flashing link LED on the device. But, if a hub is not present as a part of the network configuration, then this method does not work.
Heretofore, test instruments either provided tone or provided link pulses. This would require the technician troubleshooting the cables to select the proper type of test, tone or link pulse. If the technician desired to perform both types of tests, it would require first running one type of test, swapping in a different test instrument and then running the other type of test. Or, if one type of test was not working, the technician may wish to try the other type of test. Since it is likely that the end of the cable with the tone generating device or link pulse generating device is far away from the end of the cable where the tone is being detected or the link pulse is being observed, the operation of changing the type of test that is being performed can consume a lot of the technician""s time with multiple trips between ends of the cable, or requires that a person be stationed at each end of the cable.
Further, in the case of the link pulse testing, the technician may not know whether the port to which the link pulse generator is being attached conforms to the IEEE 802.3 MDI specification or the IEEE 802.3 MDI-X specification (the implementation of which can be performed by a switch on the network equipment or by the use of straight or crossover cables). Heretofore, test instruments required that the technician be aware of the cabling state, and connect the instrument accordingly. Thus, a technician might assume the wrong cable state, which would cause the link pulses to not be applied to the proper cable lines, resulting in no link pulses being observable at the network device connected to the other end of the cable.
In accordance with the invention, a method and device are provided that provide both a locator tone and an intermittent link on a cable to assist in identifying that cable at another end thereof. The link pulses are alternated between transmit and receive pairs.
Accordingly, it is an object of the present invention to provide an improved cable location assistance device and method.
It is a further object of the present invention to provide an improved test instrument that provides both a tone and pulsating link on a cable under test.
It is yet another object of the present invention to provide an improved apparatus and method that will cause a link indicator on an apparatus connected to a cable to intermittently flash as well as providing a detectable tone on the cable.
Another object of the present invention is to provide an improved network test instrument that alternates link pulse between wire pairs so as to provide link pulses whether or not the IEEE 802.3 MDI specification or the IEEE 802.3 MDI-X specification is employed.
The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements.